Baffle type muffler



June 14, 1949. M. F. LATHERS 3 BAFFLE TYPE MUFFLER I Filed April 11, 1946 Patented June 14, 1949 UNITED STATES PATENT OFFICE BA FFLE TYPE MUFFLER Matthew F. Lather-s, St. Augustine, Fla.

Application April 11, 1946, Serial No. 661,306

(Cl. ISL-49) 1 Claim. 1

My'invention relates to mufflers, i. e.,to devices adapted for attachment to the exhaust pipes or manifolds of internal combustion engines or the like, to deaden or materially reduce the noise of the exhaust of such engines.

It is an object of my invention to provide a mufiler for an internal combustion engine or the like, comprising a relatively long, tubular casing within which is mounted a novel bafile, or a progressive series of novel baiiles, which function or cooperate to diminish the intensity and violence of the exhaust gases to thus break up the sound producing vibrations thereof and to thereby deaden or materially reduce the noise of such exhaust.

It is aiurther object of my invention toprovide a muffler comprising efiective and efficient means for deadening or materially reducing the noise of the exhaust of an internal combustion engine or the like, and a muliler which is so constructed that the gases and vapors of the exhaust from such an engine will pass freely through the mufiler without the development therein of the objectionable and undesirable backpressure usually developed in mulilers of the prior art, which back pressure frequently results in loss of engine power and in overheating of the engine.

It is a further object of my invention to provide a muiiier in which the relative sizes of the inlet opening, muffler casing, and outlet opening, as well as the relative sizes of the openings in any and all baffles within the muffier casing, are so proportioned as to permit the exhaust gases to travel through the muffler in a flow path of gradually increasing size from the inlet opening of the mufiler to the exhaust opening thereof to thus avoid the development of backpressure within the muffler while effectively deadening or materially reducing the noise of the exhaust.

A still further object of my invention is to provide a muffler that is simple in construction and operation, that is devoid of moving parts, that is cheap and easy to manufacture and repair, that may be readily installed on the exhaust pipe or manifold of an internal combustion engine or the like as original equipment or as a replacement, and a mufiier that is highly efficient in the purposes for which designed.

In the accompanying drawings forming a part of this specification and wherein, for the purpose of illustration, I have shown a preferred embodiment of my present invention,

Fig. 1 is a side elevation of the mufller,

2 'Fig. 2 is a perspective view, partly in section, disclosing the details of the interior of the muffler,

Fig. 3 is a fragmentary perspective view, partly in section, of a portion of the muflier showing one of the bailie sections,

Fig. 4 is a horizontal sectional View of a portion of the muflier showing the baffle section illustrated in Fig. 3, and

Fig. 5 is an enlarged transverse sectional view on the line 5--5 of Fig. '1.

Referring more in detail to the drawings, wherein like reference numerals have been employed to designate like parts throughout the several views, the numeral I designates, broadly, the casing of my improved muffler, which casing may be composed of a number of individual sections 2, 3, 4, 5, and 6 secured together in end-to-end relation with adjacent sections welded or otherwise connected. Preferably the joints between the respective sections of the casing are each covered by a band 1. When thus assembled, the sections combine to produce an elongated, tubular casing, the sections and, hence, the casing, being made of iron, steel or other material sufliciently strong and durable to withstand the heat and pressure to which a device of this character is usually subjected. When attached to the exhaust pipe or manifold of an internal combustion engine, the section 2 is fitted on or within the outlet end of said pipe or manifold and the exhaust gases pass through the casing and discharge from the outer end of section 6.

The first section of the mufiler, i. e., section 2, is substantially conical in shape or configuration an open ends, the small end being adapted for attachment to an exhaust pipe or manifold of an internal combustion engine or the like, and the large end being rigidly secured to the next succeeding section 3 of the muflier. Within the section 2 is an inner, conical member 8 having its apex positioned just within the opening at the small end of section 2 and having its base portion extending for an appreciable distance beyond the large end of section 2. The inner, conical member 8 is centrally located within sections 2 and 3 and is rigidly maintained in such location within said sections by means of substantially Z-shaped brackets 9, the ends of which are welded or otherwise secured to the inner surface of section 2 and to the outer section of said conical member 8. The exterior surface of conical member 8 is provided with a plurality of spaced ribs or vanes Ill which are arranged in spiral relation on said conical surface. It is to be particularly noted that the over- 3 all length of conical section 8 is materially greater than the length of section 2 and that the angle of taper of member 8 from its apex towards its base is more acute than the angle of taper of the interior wall of section 2, thus providing an annular flow path or space of gradually increasing width from the inlet end of section 2 to the outlet end thereof.

The second section of the muffler, i. e., section 3, is substantially bulbous or barrel-shaped and, like section 2, is open at its opposite ends. Section 3 is welded or otherwise secured to the large end of section 2, the joint between these two sections preferably being covered by a band 1. It will be noted that the large end of conical member 8 terminates in a transverse plane substantially at the center of section 3.

The third section of the muffier, i. e., section 4, is substantially cylindrical and, like preceding sections 2 and is Open at its opposite ends. Section 4 is welded or otherwise secured to the outer end of section the joint between these two sections preferably being covered by a band '1. Within section #3, I rigidly secure a novel bafile H comprising at least two vertical perforated plates and at least two horizontal perforated plates disposed in cross-like or honeycomb formation. These plates are each of a width corresponding substantially to the inner diameter of the section 4, and are each of a length substantially equal to the length of said section. As will be readily apparent from the accompanying drawings, the plates are each provided with a multiplicity of perforations, the total area of said perforations being such that the flow of exhaust gases and vapors through this bafiie section is not retarded to an extent sufficient to create any back pressure within this section.

The fourth section of the muffler, i. e., section 5 is substantially cylindrical and, like the preceding sections 2, 3, and l, is open at its opposite ends. Section 5 is welded or otherwise secured to the outer end of section 4, the joint between these sections preferably being covered by a band 1'. Within section 5, I rigidly secure a novel baffle 12 composed of a plate or plates bent or otherwise formed to the shape best shown in Figs. 3 4, i. e., this baffle is substantially W- shaped as viewed in plan. The outermost portions or plates of this baffle i2 are imperforate except for a small opening .13 for a purpose to be hereinafter described. The innermost portions or plates of this bafiie 62 are each provided with a multiplicity of perforations, the total area of said perforations being greater than the total area of the perforations in the cross-like or honeycomb formation constituting the baffle II in section so that the flow of gases through sections 5 is not retarded to an extent sufficient to create any back-pressure within this section.

The fifth section of the muffler, i. e., section 6 is substantially cylindrical for a short portion of its length and tapers inwardly toward its axis to form a tapered end section having an outlet opening which is preferably substantially twice.

the diameter of the inlet opening of section 2. The large or inner end of section 6 is open, and this end is welded or otherwise secured to the outer end of section 5, the joint between these sections preferably being covered by a band i.

The sections 2, 4, 5, and 5 when secured together in axial alignment as above explained, and when provided with a conical member 8 and with baffles H and I2, constitute a muffler in which the respective sections, conical member 8 and baffles II and I2 are arranged in the manner best illustrated in Fig. 2. It will be understood, of course, that the mufiler is attached to the discharge end of an exhaust pipe or manifold of an internal combustion engine or the like, with th small end of section 2 positioned to receive the exhaust gases or vapors from said pipe or manifold, suitable supporting clamps and/or brackets being provided to rigidly attach the mufiier to the under-framing or other part of the automobile, airplane, or other device on which the engine and mufller are installed.

Referring now to the operation of the improved muffier of my present invention, and assuming that the same has been rigidly attached to the outlet end of the exhaust pipe or manifold of an internal combustion engine with the small end of section 2 receiving the exhaust gases and vapors from said engine, it is to be noted that the said exhaust gases first pass through the gradually widening annular space between the interior of section 2 and the exterior of conical member 8. Before reaching the muffler and while in the exhaust pipe or manifold, the exhaust gases and vapors are traveling in a generally spiral direction through the exhaust pipe or manifold, and this spiral and forward movement is assisted by means of the spirally arranged ribs or vanes ID on the exterior of the conical member 8. Hence, the exhaust gases and vapors travel in a true spiral path through the section 2 and into the bulbous or barrel-like section 3. As the spirally moving exhaust gases and vapors pass beyond the inner end or base of the conical member 8, they expand and are directed forwardly and inwardly toward the axis of the muffler by the gradually curved, converging walls of section 3. The spirally and forwardly moving exhaust gases and vapors next enter section 4 of the muffler where they contact and pass through the perforated plates constituting the baffle II. The contact with these plates and the passing of the gases and vapors through the multiplicity of perforations therein results in a thorough breaking up of the exhaust gases and vapors and a material reduction in the violence and intensity of the noise producing vibrations of said gases and vapors. As the total area of the multiplicity of perforations in bafile II is relatively great, no objectionable back-pressure will exist in this portion of the muffler and the gases and vapors will flow or pass freely through section 4 and through the multiplicity of perforations in the baffle II and into section 5 where they encounter the bafiie !2. It will be noted that baffle l2 has its innermost, forwardly diverging portions provided with a multiplicity of perforations, the total area of which perforations is greater than the total area of the perforations in baiiie l I in section 4 of the muflier. The exhaust gases which, by this time, have been rather completely broken up and have lost most of their initial intensity and violence, flow or pass from section 4 into and through section 5 and in so doing pass through the multiplicity of perforations in the innermost, forwardly-diverging portions or plates of baflie l2 which further diminishes the intensity and violence of the said exhaust gases and reduces to a minimum the sound producing vibrations thereof. As the total area of the multiplicity of perforations in the innermost, forwardly-diverging portions or plates of baflle I2 is greater than the total area of the multiplicity of perforations in baffle I l no objectionable back-pressure will exist in this portion of the muffler and the gases will flow or pass freely into and through section B, from which they will discharge through the outer, open end of said last mentioned section. As stated, the area of the discharge opening at the outer end of section 6 is preferably substantially twice the area of the inlet opening at the intake or smaller end of section 2 of the muffler and, hence, the exhaust gases discharge from the mufiier without the development of any objectionable back-pressure in section 6 of the muffier.

It is to be particularly noted that each of the outermost portions or plates of baffle I2 is provided at or near its forward end with an opening l3 exceeding in size the size of the individual openings in the innermost, forwardly diverging portions or plates of said baffle. By virtue of their construction, any particles of carbon or other particulate material contained in the exhaust gases and which might tend to accumulate in the apex of each of the angles where the innermost portions or plates of the baffie l2 join the outermost portions or plates thereof, will be blown through the opening l3 and into and through section 6 of th muffler. The provision of the opening I3 is quite important, as such openings effectively prevent the accumulation of carbon or other particulate material in the joints between the innermost and outermost portions or plates of the baffle l2, which accumulation might otherwise cover, clog, or otherwise render ineffective, some of the perforations in the innermost portions or plates of the baffle l2.

It will thus be seen that I have provided, by the present invention, a muffler comprising a relatively long, tubular casing containing one or more baffles which are effective to diminish the intensity and violence of the exhaust gases of an internal combustion engine or the like by breaking up the sound-producing vibrations of such gases to thereby deaden or materially reduce the noise of such exhaust. The construction is such that the gases travel through the mufller from the inlet to the outlet end thereof in a flow path of gradually increasing size or cross-section to thus permit a gradual expansion of the said gases to thus avoid the development of back-pressure and to effectively diminish or reduce the noise of the exhaust.

It will be understood that the form of my invention illustrated and described herein is to be taken as a preferred embodiment of the same and that various changes may be made in the size, shape, and arrangement of parts without departing from the spirit of my present invention or from the scope of the subjoined claim. It will be understood, further, that while in the said preferred embodiment of my invention, I have disclosed a progressive series of sections and baffles which most effectively diminish or materially reduce the noise of the exhaust, it is within the scope of my present invention to employ a lesser number of sections and baffles in instances where a complete or practically complete deadening of the noise of the exhaust is not required.

Having thus described my invention, I claim:

A mufiler comprising a tubular casing having inlet and outlet openings at opposite ends thereof and adapted to receive through its inlet opening the exhaust gases from an internal combustion engine or the like, said casing including a first section the inner wall of which gradually diverges from the inlet end of the casing toward the outlet end of said casing to form a substantially conical first section; an imperforate, elongated member of substantially conical configuration within said first section having its apex disposedadjacent the inlet opening of said casing and its base extending beyond the large end of said first section; a second section adapted to receive the exhaust gases from the first section and being of bulbous or barrel-shaped configuration, said section enclosing the base portion of said conical member and having a maximum diameter greater than the maximum diameter of said conical section and a minimum diameter corresponding substantially to the maximum diameter of said first section, the outer surface of said conical member being spaced from the inner surfaces of said first and second sections to provide therebetween a flow path of constantly increasing area for the exhaust gases as they pass through said sections; a spiral vane positioned between said spaced surfaces to impart a spiral movement to the exhaust gases as they pass through said flow path; a third section having a baffle therein, said baffle including two substantially flat perforated plates arranged in parallel spaced relation and extending longitudinally throughout substantially the length of said section, and at least two other substantially flat perforated plates arranged in parallel spaced relation and being coextensive with the first mentioned plates, said first mentioned plates and said second mentioned plates being disposed in cross-like or honeycomb formation within said third section; and a fourth section having a baflie secured therein, said baffle extending longitudinally throughout substantially the length of said third section and having two perforated portions arranged in a V formation with the apex of the V directed toward the inlet of the fourth section and the total area of the perforations in said V formation being greater than the total area of the perforations in the baffle in said third section.

MATTHEW F. LATHERS.

REFERENCES CITED The following referenlces are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,317,858 Brown Oct. 7, 1919 1,772,589 Beamer Aug. 12, 1930 1,777,522 Hamilton et al Oct. 7, 1930 1,816,245 Wolford July 28, 1931 1,916,908 Stacey July 4, 1933 2,122,086 Chase July 28, 1938 2,206,193 Kadenacy July 2, 1940 2,378,083 Hull June 12, 1945 

